In the refueling of aircraft, particularly military aircraft, it is highly desirable that refueling cycles be as short as possible. Also, as with all refueling procedures it is necessary that utmost safety be achieved.
To reduce the duration of refueling procedures refueling takes place under a pressurized system, and flexible hose, in the past, have been utilized. However, flexible hose is susceptible to damage due to wear, being crushed by vehicle wheels, and the like, and hose of such significant diameters as handle large flow capacities to shorten the fueling duration, such as 4" and 5" ID, is heavy and difficult to handle. The aircraft refueling intake ports are normally located at an elevated position requiring the refueling operator to lift the nozzle and attendant hose during connection of the hose nozzle to the port. This is a difficult procedure with large diameter hose.
To overcome the problems in refueling aircraft with relatively large diameter flexible refueling hose, to improve the durability and safety aspects of the refueling supply system, and to reduce the weight of the refueling conduit system which must be lifted by the operator during connecting the refueling system to the aircraft tank port, and removable therefrom, the rigid conduit refueling system of the invention has been invented.
It is an object of the invention to provide an all-rigid conduit refueling system wherein relatively large diameter conduits may be employed and yet the weight which must be supported by the operator is relatively low.
Another object of the invention is to provide an all-rigid conduit refueling system utilizing an elongated rigid conduit having an outer end to which a plurality of elbow couplings are mounted to achieve a universal movement of a nozzle associated with the swivel coupling chain.
Yet a further object of the invention is to provide an all-rigid conduit refueling system employing a rigid arm conduit pivotally mounted upon a support platform wherein the weight of the upper end of the arm conduit is counterbalanced and the weight of a plurality of swivel couplings mounted upon the arm conduit upper end are substantially borne by the counterbalancing structure.
The rigid conduit refueling structure of the invention is mounted upon wheeled structure for ease of positioning, and the wheeled structure includes a support platform and an outboard caster. The outboard caster includes a swivel joint having a vertical axis of rotation and the swivel joint inlet communicates with a fuel supply conduit, while the joint outlet is attached to a rigid conduit leading to the inlet of a swivel joint mounted upon the support platform having a horizontal axis of rotation. The platform mounted swivel joint outlet is connected to an elongated rigid arm conduit, and the outer end of the arm conduit communicates with a series-connected chain of elbow swivel couplings terminating in a nozzle connectable to the aircraft fuel tank port.
The weight of the arm conduit and associated swivel couplings and nozzle is borne by counterbalancing expansible chamber motors of the liquid type interposed between the support platform and the arm conduit. A control circuit is associated with the counterbalancing chambers, and the chambers include compression springs and fluid cylinders to support the weight of the arm conduit and its associated elbow swivel couplings.
The chain of series-connected elbow swivel couplings permits the nozzle to be located and angularly oriented as desired, and the mounting of the structure upon the wheeled platform and caster permits the refueling apparatus to be positioned as desired and the flexibility of a hose system is achieved without the disadvantages thereof.